The medical records of patients who had been diagnosed and followed up for NTG from 1994 to 2015 at Dong-A University Hospital were retrospectively examined.
NTG was diagnosed as glaucomatous optic neuropathy using funduscopic examination, characteristic visual field defects, open anterior chamber angles on gonioscopy, and pretreatment IOP never exceeding 21 mmHg, as measured by the Goldmann applanation tonometer (GAT).
Patients were included in the study if they fulfilled the following criteria: (1) newly diagnosed early NTG; (2) a followup period of more than 20 years; (3) a visual field test performed on patients whose follow-up lasted at least 5 years, which equated to more than 10 follow-ups with a minimum 6-month interval; and (4) 24 hr ambulatory blood pressure monitoring (24 hr ABPM) performed on patients whose follow-up lasted at least 5 years, which equated to more than 5 follow-ups with a minimum 12-month interval.
A total of 158 NTG patients were followed over 20 years.
Among the 72 NTG patients, 28 patients (38.9%) showed glaucomatous visual field progression.
The CNTGS reported that annual decrease in MD was -2 dB in NTG .
NTG was diagnosed according to the third edition of the Japan Glaucoma Society's Glaucoma Diagnosis Guidelines.
In the present study of NTG patients, PG monotherapy was continued in one eye and while the contralateral eye was switched to PG/b fixed combination therapy.
In combination with timolol, one report stated that the addition of timolol to latanoprost therapy in NTG reduced intraocular pressure by 24% .
According to the Japanese Glaucoma Diagnosis Guide-lines, the goal of NTG therapy is to reduce intraocular pressure by 20% from BL or, in severe cases, 30%.
For example, travoprost/timolol fixed combination eye drops can effectively reduce intraocular pressure with a lower risk of corneal disorder [21, 22] in Japanese patients with primary open-angle glaucoma (POAG) and NTG [7, 23].
In the present study, switching from PG monotherapy to PG/b fixed combination therapy for NTG resulted in a greater intraocular pressure reduction than PG alone without increasing the number of instillations, thereby maintaining patient adherence.